Assessing an Embryo for Genetic Defects
- Posted on: Nov 12 2013
For those parents or partners who want to bring a life into the world, there is no fault in wanting to test the potential embryo for any and all potential defects. The most often used method for this screening is a combination of PGD (Preimplantation genetic diagnosis) and PGS (Pre-implantation genetic screening).
These two tests are performed to check the chromosomal composition of an embryo from genetically normal parents, and are most often performed by couples who have an increased chance of producing a chromosomal abnormality in an offspring.
When is PGS (Pre-implantation genetic screening) used?
PGS is only used in embryos at risk of being carriers for a chromosomal defect and will not alert the couple to the potential for genetic disorders. This makes it ideal to scan for potential ailments such as Down’s syndrome, but will not make the couple aware if their embryo is at risk for something such as cystic fibrosis.
PGS is used when the female partner of a couple is above the age of 35, producing an increased risk of bearing a child with a chromosomal abnormality. If the couple has had miscarriages in the past without a known cause, or has had an unsuccessful IVF cycle previously, PGS is ideal in potentially preventing a defective embryo from being used.
When is PGD (Pre-implantation genetic diagnosis) used?
PGD scans are used when one member of the couple is known to carry a chromosomal defect, or if the embryo of the couple is thought to be of risk of having a child with a single gene disease inherited from a parent. If the couple has had a previous pregnancy with the presence of an abnormality, PGD scans can help to prevent this from occurring a second time.
This testing is performed through the use of in vitro fertilization, and functions by maturing multiple eggs that have been retrieved from the prospective mother. These oocytes are then inseminated and grown while monitored in cultures. A 1 to 2 cell biopsy is performed, which does not damage the cells remaining in the egg. These isolated cells are used in the evaluation of the embryo in order to confirm the presence of an anticipated defect.
The testing used in these methods is very reliable, and can help to inform a couple if their embryo has the potential of producing a genetic abnormality. In both PGS and PGD, the embryo is not harmed and is readily available for use if the testing proves its validity.
Rocky Mountain Fertility Center offers one of the top fertility doctors in Colorado, Dr. Deborah Smith. For over 20 years, she has been offering comprehensive fertility treatments to help women reach their fertility goals. This includes PGD, IVF, ICSI and much more.
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